Might be a good idea to limit the amount of characters that can be used before someone comes up with "everyone" or lists over 100.
Eruruu (Utawarerumono) — Every team needs a healer. :o
Henrietta (Gunslinger Girl) — Everyone agrees that the FN P90 is awesome.
Lucy (Elfen Lied) — Four vectors (basically invisible arms) that can kill anything instantly within two metres, as well as render her bulletproof.
Mariko (Elfen Lied) — Twenty-six vectors with a range of eleven metres.
Nana (Elfen Lied) — Four vectors with a range of five metres.
Rico (Gunslinger Girl) — My sniper for the battle.
Saber (Fate/ Stay Night) — OMG AN HUEG SWORD! Indeed.
Triela (Gunslinger Girl) — Shotguns are fun, no?
To be honest I'd just use Sakuya Iyazoi from Toho (ability to stop time, 'nuff said), but that's a game series, not an anime one. T_T